Several processing approaches exist for making high density refractory metal products. Such processes include rolling, HIP'ing (hot isostatic pressing), and hot pressing. Typical processes are described in U.S. Pat. Nos. 3,116,146, 4,612,162, 4,670,216, 4,731,116, 5,470,527, 5,594,186, 5,774,780, 6,165,413, 6,328,927, and 6,350,407. Rolling, hot pressing and HIP'ing have been widely used for making high-density plates for physical vapor deposition (“PVD”) (e.g., for use as sputtering targets). Sintering techniques have not been employed in the production of sputtering targets because of an inability to consistently achieve high enough density.
The present invention is directed to a process for making refractory metal products, and particularly sputtering targets, by pressing and sintering of powders. The invention is also directed to thin films produced from such sputtering targets.